Well, there's the old Chinese curse, "May you live in interesting times." And in that sense of the word...
My feeling is that there are two possible approaches to ecological building;
1. Modernistic: which is the approach more discussed above on this thread, and about which I can contribute little.
2. Traditional.
I look more for inspiration to very traditional approaches. I would guesstimate that my great-great-grandparents, all 16 of them combined, had a carbon-footprint similar or lower to a single individual living today. Yet evidence suggests that they all survived to reproductive age.
Before World War Two, say, the transport of building materials was much more difficult and expensive. It was a huge advantage to source materials locally.
If you look at virtually any traditional charming country cottage, with roses growing around the door, you can usually find the source of the stone used to build it within a kilometre or so. It is extremely rare to find one without a fresh water supply within a few dozen metres.
Traditionalbuilding techniques were often also quite energy-effective, with solid thick walls providing both good insulation and acting as thermal storage heaters; smaller window openings conserving heat better. Shutters and curtains are more efficient insulators than blinds.
Cob, or torchis(French),
http://en.wikipedia.org/wiki/Cob_%28material%29http://fr.wikipedia.org/wiki/Torchis...is the traditional building material par excellence. Ur in Mesopotamia was built of cob.
I stumbled across it while working on a half-timbered wall in France, which I was repairing. I started by scraping back the old torchis, then applying a thick layer of modern crepi (lime-based render) over the top. As I continued with this, I began to find that the 200 year old torchis, sieved and remoistened, was a much easier material to use than the modern, expensive, high-carbon equivalent. As this saved me several trips to ther tip, reusing the old material actually saved me money on fuel, in itself.
Altogether, I've now used old cob, scraped down off old walls, etc, to reface around 50 squared metres of wall, and as mortar, to rebuild a couple of cubic metres of masonry. I think its a fantastic material, and with cement/plaster production accounting for around 5% of CO2 emmissions, its use is very highly commended.
I have never mixed my own from scratch; and therein lies a problem. I find that there are definite local characteristics to the old materials I am reusing. "Mud" varies from place to place - and presumably local traditions have grown over time regarding the correct additional ingredients to add to make the local mud better-behaved.
Among these additional ingredients; lime, straw/hay and horse/donkey droppings.
The presence of the last I find especially notable, and gloriously pragmatic. You turn up on site in the morning, having corralled the draft animals on site overnight, and find that they have produced more building materials while you slept.
Anyway, I now have to get back to scraping shite up the walls. "Interesting", my arse!
;(